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Preserve application code's errno in rtld locking code, it attemps to keep

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any case safe.
This commit is contained in:
David Xu 2008-03-20 09:35:44 +00:00
parent 42b5d159f2
commit 8c38215f50
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=177445
1 changed files with 31 additions and 2 deletions
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33
lib/libthr/thread/thr_rtld.c
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@ -36,6 +36,9 @@
#include "rtld_lock.h"
#include "thr_private.h"
#undef errno
extern int errno;
#define CACHE_LINE_SIZE 64
#define WAFLAG 0x1
#define RC_INCR 0x2
@ -88,20 +91,38 @@ _thr_rtld_lock_destroy(void *lock)
free(l->base);
}
#define SAVE_ERRNO() { \
if (curthread != _thr_initial) \
errsave = curthread->error; \
else \
errsave = errno; \
}
#define RESTORE_ERRNO() { \
if (curthread != _thr_initial) \
curthread->error = errsave; \
else \
errno = errsave; \
}
static void
_thr_rtld_rlock_acquire(void *lock)
{
struct pthread *curthread;
struct rtld_lock *l;
long v;
int errsave;
curthread = _get_curthread();
SAVE_ERRNO();
l = (struct rtld_lock *)lock;
THR_CRITICAL_ENTER(curthread);
atomic_add_acq_int(&l->lock, RC_INCR);
if (!(l->lock & WAFLAG))
if (!(l->lock & WAFLAG)) {
RESTORE_ERRNO();
return;
}
v = l->rd_cv;
atomic_add_int(&l->rd_waiters, 1);
while (l->lock & WAFLAG) {
@ -109,6 +130,7 @@ _thr_rtld_rlock_acquire(void *lock)
v = l->rd_cv;
}
atomic_add_int(&l->rd_waiters, -1);
RESTORE_ERRNO();
}
static void
@ -117,14 +139,18 @@ _thr_rtld_wlock_acquire(void *lock)
struct pthread *curthread;
struct rtld_lock *l;
long v;
int errsave;
curthread = _get_curthread();
SAVE_ERRNO();
l = (struct rtld_lock *)lock;
_thr_signal_block(curthread);
for (;;) {
if (atomic_cmpset_acq_int(&l->lock, 0, WAFLAG))
if (atomic_cmpset_acq_int(&l->lock, 0, WAFLAG)) {
RESTORE_ERRNO();
return;
}
v = l->wr_cv;
atomic_add_int(&l->wr_waiters, 1);
while (l->lock != 0) {
@ -140,8 +166,10 @@ _thr_rtld_lock_release(void *lock)
{
struct pthread *curthread;
struct rtld_lock *l;
int errsave;
curthread = _get_curthread();
SAVE_ERRNO();
l = (struct rtld_lock *)lock;
if ((l->lock & WAFLAG) == 0) {
@ -162,6 +190,7 @@ _thr_rtld_lock_release(void *lock)
}
_thr_signal_unblock(curthread);
}
RESTORE_ERRNO();
}
static int